A large number of legal lotteries exist today, and many are of an instant variety, that is, the purchaser of a ticket can learn immediately whether or not he or she has won a prize. The most common of these instant lotteries involve the sale of individual lottery tickets which have prize information printed beneath some opaque ink that is rubbed off by the purchaser to determine whether or not a prize has been won. The prize information (or lottery number) is printed on those tickets and covered with an opaque ruboff layer and a "confusion" pattern. The latter prevents the prize information from being read without scratching off the ruboff layer. The prize information, the opaque layer and the confusion pattern are all added to the ticket during the manufacturing process.
The fact that the prize information is printed on the ticket at the time of its manufacture creates some problems. First, printing the prize information on each ticket as it is manufactured makes the manufacture of the tickets a very involved and expensive process (as the prize indicia must change with almost every ticket). Secondly, and more importantly, if the tickets are stolen prior to sale, they already contain the prize information, and any winning tickets could be wrongfully redeemed.